benjamin



2 Sheets-Sheet 1.

(No Model.)

8. EBENMMIN. UNDERGROUND PIPE 0R GONDUIT EUR ELECTRICAL CONDUCTORS.

Patented Aug. 5, 1884.

INVBTOR WITNBSSBS;

N. PETERS, Pnoxn'ulhogmpnei, washington. D. C.

2 Sheets-Sheet 2.

(No Model.)

G. H. BENJAMIN.

UNDERGROUND PIPE 0E GONDUIT EOE ELECTRICAL GONDUGTOES.

INVENTOR M )76E ATTORNEY S Patented Aug. 5, 1884.

if@ W gw E.

UNITED STATES Eri'rnur Ormea.

GEORGE H. BENJAMIN, vOF SHORT HILLS, NEV JERSEY.

UNDERGROUND PIPE R CONDUIT FOR ELECTRICAL CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 302,883, dated August5, 1884:.

Application filed January 8, 1884. (No model.)

'To @ZZ whom t may concern,.-

Be it known that I, GEORGE H. BENJAMIN,

Jersey, have invented certain new and useful Improvements in UndergroundPipes or .Conduits for Conveying Electrical Conductors, of which thefollowing is a specification, reference 'being had to the accompanyingdrawings, forming a part thereof.

My invention relates to an underground conduit for wires or conductorsof electrical currents, in which said wires are suitably insulated fromeach other and inclosed in a pipe.

My invention also has for its object to provide means whereby such wirescan be wholly taken out of the inclosing pipe or conduit, or whereby abranch wire or wires can be connected to one or more of said inelosedwires without disturbing the body of the pipe or conduit or the otherwires contained therein without 'breaking joints.

In the accompanying drawings, in which similar letters of referencerepresent like parts, Figure l is an exterior view of the pipe orconduit inclosing the wires orelectrical conductors, showing the offsetsof the coup-y ling-boXes tapped and the wires leading there from. Fig. 2is a longitudinal section taken through the line my of Fig. 3. Fig. 3 isa double transverse section taken on parallel planes, so as to show thehollow split conical tappingplug and the straight plugs for dividing thewire. One ofthe lastsmentioned plugs is shown partially removed, with apiece of insulating material inserted in its sock et. Fig. 4 is alongitudinal section of the pipe or conduit with a transverse section ofthe cap or plate attached to the end thereof, as the same-is to be usedwhen the pipe or conduit is carried into a man-hole, testing-box, orstation. Fig. 5 is an elevation of the hollow conical split plug. Fig. 6is a longitudinal section of the conical plug, showing the relativepositions of the wire, its covering, hard-rubber insulator, and theplug. Fig. 7 is a transverse section of the conical plug, rubberinsulatingtube, and covered wire.

' In the drawings, A is a pipe or tube, made preferably of sheet-iron orpaper rolled in hot liquid asphalt. It can be made of any requireddiameter or length. In practice, length of fifteen feet will be foundmost convenient.

B B are the coupling-boxes for connecting the ends of theconduitsections together, made of cast-iron, having flanges orprojections D, the face of one' flange being recessed to receive aprojection on the face of the other flange. The boxes are boltedtogether, and may be attached to the pipe by rivets, shrinking, or inany well-known way. On the coup ling-boxes are sleeves B, in whichsleeves are tapped conical screw-threaded holes to receive the hollowconical split plug C.

C is a hollow conical plug, screw-threaded, and having a split orchannel, C, cut through one sidethereof or partially curved around theplug, as shown in Fig. 5. The object of cutting the plug through, asdescribed, is that whenv said plug is inserted in the'screw-threadedopening in the sleeve B and firmly screwed down the diameter ofthecylindrical opening in the plug is decreased and the rubberinsulating-tube within the plug is compressed around the wire which isled through said plug, holding the sameiirinly.

The flanges or projections D on the coupling-boxes have a screw-threadedhole, F, tapped through them to receive the straight screw-threadedplugs E. rlheseholes are made through both parts of the lianges D, sothat when the said flanges are in contact the plug is inclosed by bothof them.

G are the tubes containing the wires or elect-rical conductors, and canbe made of any nonconducting material, but preferably of paper rolled inhot liquid asphalt. s

H is the insulating material, placed between the wire-conveying tubes Gandcompletely surrounding them. Various compounds can be used for thispurpose, as a mixture of tar and asbestus, hydraulic cement, meltedparafline, 85e. All of these compounds are, however, open to theobjection that they are more or less affected by heat and cold. Itherefore prefer to use a fine quali-ty of mineral wool to surround thewire-conducting tubes. The particular method of applying the mineral isnot herein shown or described, as I intend to make the same the subjectof a separate application.

I I are disks of soft rubber attached to the faces of thecoupling-boxes, and having holes IOO provided to receive the ends oi'the tubes which convey the wires or electric conductors.

J J are the wires or electrical conductors, shown only in the outertubes, the other tubes being represented as empty.

L L are branch conducting-wires connected to the wires J and passingthrough the split conical plugs. These wires L serve to convey the wholeor a portion of the electric current from the main wire J. The branchconductingfwires are surrounded with an envelope, M, of lead or asuitable non-conducting substance.

N is a hardrubber tube, closely fitting inside the split conical. plug.This rubber tube is also split or divided on one side in manner similarto the plug which incloses it, so

. that it may be contracted upon the covering ofthe branchcomlucting-wire by the pressure exerted upon it by the split conicalplug C.

O, Fig. (5, is a cap screw-threaded into the top of the conical plug,and is intended to be used to cover the top of the plug and rubberinsulating-tube- Vhen the main pipe or conduit terminates in a man-hole,testing-boX, or station, the end is covered with an iron cap, P, asshown in Fig. et. rlhe conical split plugs are then tapped into the faceof the said cap or plate, which is insulated from the pipe or conduit bythe rubber l.

From the above description the arrangement of the various parts of thepipe or conduit, and also the means employed for taking out wires orconnecting branch wires, will be readily understood.

In practically applying the device I prefer to have the sections ol" thepipe or conduit in length of from thirteen to iifteen feet, and of asuilicientdiamcterto allow theinclosed asphalted-paper tubes containingthe conductors to be at least one-half of an inch apart, the interveningspace to be filled with the noneonducting material. As 'the pipes orconductors are laid, the sections are bolted together by bolts passingthrough the iian ges D, and in the conical tapped holes in the flanges Bof the coupling-boxes are placed solid conical screw-threaded plugs. Thenumber of tapped holes in the ilange may be equal to the number of wirescontained in the outer circumferential row, so that any one or all ofthe wires may have branches connected to them, as desired. In arrangingthe wires in the pipe or conduit those intended to be used asthrough-wires between distant points should be placed in the center oithe pipe, and those intended to supply local circuits in the outercircumferential row. Vhere it is desired to connect a branch wire to oneoi' the wires of said outer row, the solid conical plug` iirst insertedis removed. rlhe insulating material between the internal surface of themain pipe and the paper conductingtube is cut away, and a hole is thenmade through the paper tube which incloses the wire to be reached. Thewire through which the branch current is to be carried may either havean ordinary insulatingcovering or be inelosed in a lead pipe. The end ofthis wire,being denuded of its covering for a short distance, is carriedthrough the split rubber insulating-tube contained in the hollow splitconical plug, and is inserted into the aperture made in the main pipeuntil it meets the denuded line-wire, to which it may be soldered orelectrically connected in any convenient way. Union having been made,the hollow conical split plug and rubber insulating-tube surrounding thebranch wire are inserted into the conical tapped hole and screwed iirmlydown. it will be obvious that the more the plug is forced down thetighter it holds the rubber insulating-tube7 which in its turn holds thecovered branch conducting -wire. Melted paralline is now poured intothehollowofthe plug, so as to lill up any interstices, and the cap ontop of the plug may then be allixed.

lVherc it is desired to carry out the whole current conveyed by a mainwire-as, :l`or example,the lowermost wire, T, Fig. 2-the cylindricalbolt E, Fig. $3, is removed, a cutting instrument is inserted in itssocket, and the wire is thus divided. A piece ot' insulating material,K, Fig, is next inserted, so as to separate the eut ends o'fvthe wire,and around this insulating material melted parai'ine is poured. The plugis then reinserted and screwed firmly down. The conductingwire leadingout from the main wire thus cut is connected to the line in the manneralready above described with reference to branch wires. 1

In laying the pipes or conduits it is usual te have manholes ortestingboxes located at certain distances apart, and means must beprovided whereby the wires can be tested, a portion of them divertedinto a branch conduit, or defective wire removed. This is accomplishedby means of the plate l?, Fig. 4A, which its closely over the end ol'the pipe, and is provided with conical plugs, and openings arranged insaid plate and in a line with the paper tubes conveying the electrical,conducttors. When a wire is connected to the main wire,the hollowconical split plugs are applied, as previously described.

l claim as my inventionl. In combination with a pipe or conduit forconveying electrical conductors, two or more wire-conveying tubescontained therein, a plate or cap attached to the end ot' thepipesection, a plate ol' insulating material located between the pipeand said plate, conical. holes tapped through said plate in a line withthe wire-conveying tribes, a hollow conical screw threaded split plugadapted to `fit said tapped holes, and a hard-rubber splitinsulatingtube within said hollow plug, substantially as described.

2. The combination, substantially as hereinbeiore set forth, ol" theplate Il), through which conical holes have been tapped, with the I (DOIIO hollow conical screw-threaded split plug C, split hard-rubberinsulating-tube N, and the plate of insulating material I.

3. rlhe combination, substantially as hereinbefore set forth, of a pipeor conduit, a coupling-box attached to the end or ends thereof, two ormore sleeves upon said couplingbox, conical and straight holes tappedthrough said sleeves, and a hollowconical screw-threaded split plug, anda straight screw-threaded plug adapted, respectively, to fit said tappedholes.

4. The combination, substantially as hereinbefore set forth, of acoupling-box, disk of insulating material attached to the faces of theadjacent coupling-flanges, two or more sleeves located upon the outsideof the couplingboxes, conical and straight holes tapped through saidsleeves, hollow conical screwthreaded `split plugs containing ahard-rubber split insulatingtube adapted to fit the conical tapped hole,and a straight screw-threaded plug to fit the straight hole.

5. The combination, substantially as llereinbefore set forth, of a mainconducting-wire and the means whereby a portion of the current conveyedby said wire can be carried out of the inclosing pipe or conduit,consisting of the branch conducting-wire, the split rubberinsulating-tube, and the hollow conical screw-threaded plug adapted tofit theconical hole tapped in the sleeve of the coupling-box.

6. The combination, substantially as hereinbefore set forth, of' a mainconducting-wire and the means whereby the whole of the current conveyedby said wire can be carried out at the inclosing pipe or conduit,consisting of a divided main conducting-wire having inserted between thedivided ends thereof a piece of insulating material through the straighthole tapped in the sleeve of the coupling-box, said insulating materialbeing held in its place by a straight screw-threaded bolt adapted to fitthe tapped hole and the branch conducting-Wire, the split rubberinsulatingtube, the hollow conical split plug, and the conical holetapped in the sleeve of the coupling-box.

7. A branch conducting-wire, L, in combination with the split rubberinsulator N and the hollow conical screw-threaded split bolt C,substantially as described.

8. A branch conducting-wire, L, in combination with the split rubberinsulator N, the hollow conical screw-threaded bolt G, and cap O,substantially as described.

9. The combination of the main inclosingpipe A, interiorconducting-pipes, G, the coupling-box B, having the sleeves thereon, BD, tapped to receive the conical bolt C, and the straight bolt E,substantially as described.

10. The combination of the coupling-box B, having the sleeves B andflange D thereon tapped to receive the conical bolt C, and the straightbolt E, substantially as described.

GEO. H. BENJAMIN.v

